hugetlb: introduce generic version of huge_pte_none()

arm, arm64, ia64, mips, parisc, powerpc, sh, sparc, x86 architectures use
the same version of huge_pte_none, so move this generic implementation
into asm-generic/hugetlb.h.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Alexandre Ghiti <[email protected]>
Reviewed-by: Luiz Capitulino <[email protected]>
Reviewed-by: Mike Kravetz <[email protected]>
Tested-by: Helge Deller <[email protected]>			[parisc]
Acked-by: Catalin Marinas <[email protected]>	[arm64]
Acked-by: Paul Burton <[email protected]>		[MIPS]
Acked-by: Ingo Molnar <[email protected]>		[x86]
Cc: Arnd Bergmann <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James E.J. Bottomley <[email protected]>
Cc: James Hogan <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Russell King <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
index ffa63fd..2fc3d68 100644
--- a/include/asm-generic/hugetlb.h
+++ b/include/asm-generic/hugetlb.h
@@ -73,4 +73,11 @@ static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
 }
 #endif
 
+#ifndef __HAVE_ARCH_HUGE_PTE_NONE
+static inline int huge_pte_none(pte_t pte)
+{
+	return pte_none(pte);
+}
+#endif
+
 #endif /* _ASM_GENERIC_HUGETLB_H */